Re: Add flipped fmap

On Thu, 2010-04-08 at 14:04 -0300, Felipe Lessa wrote:

On Thu, Apr 8, 2010 at 9:45 AM, Bas van Dijk wrote:

...

I must say that Brent Yorheys comment about (<**>) not being flip (<*>) has made the 'symmetry' argument less convincing and has moved me a bit closer to the - camp. However, I'm still for adding it because it can make code nicer.

They -- <**> and <$$> -- are symmetric in spirit.

The equational law relating <$> to <*> for Applicative instances is f <$> a = return f <*> a We analogously have a <$$> f = a <**> return f as well. So the analogy between <$$> and <**> holds. jcc